Arc joint plier

ABSTRACT

An arc-type slip plier having an arcuate lug and arcuate grooves facing the plane of the jaw cavity with the pivotal axis the jaw head portions located between the plane of the jaw cavity and the area of engagement of the arcuate lug and the arcuate grooves.

ilited States Patent [191 3/1934 Manning 81/414 Martin Dec. 17, 1974 ARCJOINT PLIER 2,766,647 10/1956 Patrick 81/414 ,44,6 71958 H d'k ..8l385[75] Inventor: Ralph Martin, Colorado Springs, 2 8 0 l I en no son I xColo. FOREIGN PATENTS OR APPLICATIONS I [73] Assignee: Western ForgeCorporation, 1,808,209 6/1969 Germany 81/414 Colorado Springs, Cola36,853 5/1912 Sweden 8l/409 [22] Filed: 1973 Primary Examiner-James L.Jones, Jr. [21 Appl. No.: 405,860 Attorney, Agent, or Firm Bruce G.Klaas [52] US. Cl. 81/414 [57] ABSTRACT 1g An arc-type slip plier havingan arcuate lug and arcu- 07 41 ate grooves facing the plane of the jawcavity with the pivotal axis the jaw head portions located between theplane of the jaw cavity and the areaof engagement of [56] Referencescued the arcuate lug and the arcuate grooves.

UNITED STATES PATENTS 950 3 2 i g 1 Claim, 2 Drawing Figures BACKGROUNDAND SUMMARY OF INVENTION This invention relates to an improvement in anarctype slip plier which has conventionally been provided with anarcuate lug and arcuate grooves which face away from the plane of thejaw cavity so as to define a pivotal axis located a substantial distancefurther beyond the plane of the jaw cavity than the area of engagementbetween the arcuate lug and the arcuate grooves. In the presentinvention, the arcuate lug and arcuate grooves face toward the plane ofthe jaw cavity with the pivotal axis located at or between the plane ofthe jaw cavity and the area of engagement between the arcuate lug andthe arcuate grooves.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is partial side ,elevationalview of a conven- DETAILED DESCRIPTION OF THE INVENTION Referring firstto'FIG. 1, a conventional arc-type plier is shown to comprise an upperjaw memberl2 having a jaw head portion 14, with a relatively flatgripping surface 16 thereon, and a handle portion 20, only a portion ofwhich is shown, extending transversely relative to the jaw headportion.. A lower jaw member 22 is provided with a jaw head portion 24,having a relatively flat gripping surface 26 thereon, and a handleportion 28,.only a portion of which is shown, extending transverselyrelative to the jaw head portion. Arc-type groove means are provided onone handle portion by a series of grooves'30 extending along arcs havingtheircenters located a substantial distance below the jaw cavity 32along the centerline 34 of pivot pin slot 36 which is centrally formedin handle portion 20. Arctending through an opening 40, in the other jawhandle 28, which opening is in spaced relationship to the lug member 38along centerline 34 and through the aligned slot 36. The arrangement issuch'as to permit the arcuate lug 38 to be selectively placed in any oneof the arcuate grooves 30. In the uppermost position of, FIG. 1, thepivotal axis 42 is spacedrfrom a plane 44, including the grippingsurface 26, (sometimes referred to hereinafter as the plane of the jawcavity) by a substantial distance x with the result that the outermostpoint 46 of lower jaw head portion 24 moves outwardly relative to upperjaw head portion 14 along an are 48 a distance y which can be somewhatdisadvantageous in attempting to use the tool in confined circumstances.More importantly, the prior art arrangement is such as to cause thefulcrum to lie in a plane 50 extending obliquely relative to thegripping surface 26 resulting in unequal distribution of gripping forcestherealong.

Referring now to FIG. 2, wherein similar parts are referred to by thesame numbers, the arcuate. grooves 30 and arcuate lug 38 have beenreversed so as to face the plane of the jaw cavity with the arcuatecenters of the grooves and lugs as well as the pivotal axis of the jaw lportions being located on the plane of the jaw cavity in the uppermostlug position and located between the lug 1 and the plane of the jawcavity in all other positions. In this manner, the distances x and y arereduced, to approximately zero in the uppermost lug-groove position,with point 46 remaining behind the vertical plane 50, which includes theoutermost point on the upper jaw portion 14, as the point 46 isvariously located along are 48. In addition, the plane of the fulcrum 50is substantially coincident or parallel with the plane of the jaw cavityin the gripping position. I

Thus, although the new and improved structure comprises a reversal ofknown structure, new and improved results are obtained which provideimproved operating characteristics.

I claim: 1. An are joint slip-type plier tool comprisingi a first jawmember having a jaw head portion with an elongated gripping surfacethereon and a handle portion extending generally transversely therefrom,v I l a second jaw member having a jaw head portion with -an elongatedgripping surface thereon and a handle portion extending generallytransversely therefrom, the elongated gripping surfaces on said'firstjaw member and the elongated gripping surface on said second jaw memberfacing one another in generally parallel relationship and defining a jawcavity jacent the handle portions and terminating outwardly in ajaw'cavity opening defined by terminal transverse outer surfaces of saidjaw portions,

an elongated slot in one of the handle portions extending-atsubstantially a right angle to the elongated gripping surfaces" anddefined by spaced parallel side surfaces on opposite sides of a centrallongitudinalaxis of said slot,

pivot pin means slidably rotatably mounted in said slot between saidspaced parallel side surfaces and pivotally connecting the handleportions for pivotal movement relative to one another between an openjaw cavity position and'a closed jaw cavity position and slidablyconnecting the handle portions for sliding adjustment along said slot tovariably adjusted positions to vary the. spacing between the elongatedgripping surfaces in the closed jaw cavity position, i

said pivot pin means having a pivotal axis extending transversely of andlocated in general coplanar relationship with said centrallongitudinal'axis of said slot and with said elongated gripping surfaceon said second jaw portion in all of said variably adjusted positions,

an arc-type lug means on one of the handleportions and located andspaced axially along said central longitudinal axis .of said slot fromsaid pivot pin means beyond said jaw cavity and having a radius ofcurvature extending toward and coaxial with said pivotal axis of saidpin means,

a plurality of arc-type groove means on the other of the handle portionseach being separately slidably rotatably cooperable with said arc-typelug means and having a radius of curvature extending toward saidpivotal'axis of said pin means and having a radiusof curvature of equallength to the length of the radius of curvature of said arc-type lugmeans,

therebetween terminating inwardly and closed adsaid pin means and saidpivotal axis provided there by the transverse terminal outer surfaces ofsaid jaw portions being substantially aligned and coterminous in each ofsaid adjusted positions when the jaw portions are in the closed jawcavity position and the path of relative movement of said transverseterminal outer surfaces of said jaw portions in each of said adjustedpositions during movement between said closed jaw cavity position andsaid open jaw cavity position being arcuate about said pivotal axis ofsaid pin means whereby the distance between said terminal transverseouter surfaces of said jaw portions and the central longitudinal axis ofsaid slot in any open jaw cavity position is always equal to or lessthanthe distance between said terminal transverse outer surfaces of said jawportions and the central longitudinal axis of said slot in said closedjaw cavity position.

1. An arc joint slip-type plier tool comprising: a first jaw memberhaving a jaw head portion with an elongated gripping surface thereon anda handle portion extending generally transversely therefrom, a secondjaw member having a jaw head portion with an elongated gripping surfacethereon and a handle portion extending generally transversely therefrom,the elongated gripping surfaces on said first jaw member and theelongated gripping surface on said second jaw member facing one anotherin generally parallel relationship and defining a jaw cavitytherebetween terminating inwardly and closed adjacent the handleportions and terminating outwardly in a jaw cavity opening defined byterminal transverse outer surfaces of said jaw portions, an elongatedslot in one of the handle portions extending at substantially a rightangle to the elongated gripping surfaces and defined by spaced parallelside surfaces on opposite sides of a central longitudinal axis of saidslot, pivot pin means slidably rotatably mounted in said slot betweensaid spaced parallel side surfaces and pivotally connecting the handleportions for pivotal movement relative to one another between an openjaw cavity position and a closed jaw cavity position and slidablyconnecting the handle portions for sliding adjustment along said slot tovariably adjusted positions to vary the spacing between the elongatedgripping surfaces in the closed jaw cavity position, said pivot pinmeans having a pivotal axis extending transversely of and located ingeneral coplanar relationship with said central longitudinal axis ofsaid slot and with said elongated gripping surface on said second jawportion in all of said variably adjusted positions, an arc-type lugmeans on one of the handle portions and located and spaced axially alongsaid central longitudinal axis of said slot from said pivot pin meansbeyond said jaw cavity and having a radius of curvature extending towardand coaxial with said pivotal axis of said pin means, a plurality ofarc-type groove means on the other of the handle portions each beingseparately slidably rotatably cooperable with said arc-type lug meansand having a radius of curvature extending toward said pivotal axis ofsaid pin means and having a radius of curvature of equal length to thelength of the radius of curvature of said arc-type lug means, said pinmeans and said pivotal axis provided thereby being movable along saidslot to a plurality of variably displaced positions whereat saidarc-type lug means is slidably rotatably cooperably associated withvarious separate ones of said arctype groove means for relativerotatable sliding movement about said pivotal axis of said pivot pinmeans, the transverse terminal outer surfaces of said jaw portions beingsubstantially aligned and coterminous in each of said adjusted positionswhen the jaw portions are in the closed jaw cavity position and the pathof relative movement of said transverse terminal outer surfaces of saidjaw portions in each of said adjusted positions during movement betweensaid closed jaw cavity position and said open jaw cavity position beingarcuate about said pivotal axis of said pin means whereby the distancebetween said terminal transverse outer surfaces of said jaw portions andthe central longitudinal axis of said slot in any open jaw cavityposition is always equal to or less than the distance between saidterminal transverse outer surfaces of said jaw portions and the centrallongitudinal axis of said slot in said closed jaw cavity position.